The field of the present invention relates to enclosed trailers and used for the transport of cargo. More particularly, the present invention relates to a plate coupling system for assembling the trailers.
Commercial tractors and other types of trucks transport cargo using trailers such as van-type trailers and other types of enclosed trailers. As illustrated in FIG. 1, a van-type trailer 10 includes a floor 15, a roof (not shown) and two sidewalls 25. A front bulkhead 30 and a rear door or doors (not shown) enclose the trailer 10. A king-pin 40 located at a forward area of the trailer 10 couples to a fifth wheel on a tractor and a conventional wheel assembly 35 and front landing gear 45 support the trailer 10.
Federal regulations specify a maximum width 12 of about 102{fraction (3/8 )}inches for enclosed trailers 10. Generally, this is measured between the exterior surfaces of the trailer sidewalls 25. In addition, the transport industry has cargo carrying standards that require a width of about 101xc2xcinches inside the trailer 10. This width is generally measured between the interior surfaces of the sidewalls 25. When combined, the Federal and industry requirements define a maximum sidewall thickness 82 of about {fraction (9/16)} of an inch, shown in FIGS. 2-3. The sidewall thickness 82 is therefore constrained by the limits imposed by both the Federal regulations or the industry standards.
Illustrated in FIGS. 1-3, the sidewalls 25 of conventional van-type or other enclosed trailers are generally constructed of a plurality of generally rectangular plates 50. Each plate 50 is connected by elongaged joiners 55. Fasteners 65 attach the plates 50 to the joiners 55. FIG. 2 illustrates two plates 50 attached to joiner 55 by fasteners 65. Also illustrated in FIG. 2, the sidewall thickness 82 is the sum of the plate thickness 85 and the joiner 55 thickness 80. The outside-facing surface of each joiner 55 is used to define the maximum width of the trailer 10, and the inside-facing surface of each plate 50 is used to define the inner, or enclosed width of the trailer 10.
When the outside-facing surface 70 of each joiner 55 defines the maximum Federally regulated width of the trailer 10, and the inside-facing surface of each the plate 50 defines the minimum industry standard inner width of the trailer 10, if the plate thickness 85 or the joiner thickness 80 is changed, the other member must change to maintain the necessary sidewall thickness 82. For example, it may be advantagous to add a cargo control member to the sidewall 25. A cargo control member is an elongated plate having a plurality of holes and/or slots for attaching straps, hooks and other devices to position and secure the cargo within the trailer 10. Illustrated in FIG. 3, the inclusion of a cargo control member 60 requires a plate thickness 87 that is smaller than the plate thickness 85 of FIG. 2. The larger joiner thickness 89 maintains the required sidewall thickness 82. A thinner sidewall 25 cannot be used, as it does not have the structual strength necessary to restrain the cargo during transportation.
Alternatively, a thicker plate 50 may be installed to increase the structural strength of the sidewall 25 in the area adjacent to the cargo-loading end of the trailer 10. The trailer 10 opening where cargo is loaded can sustain impacts from the cargo or from fork-loaders placing the cargo into the trailer 10. In this instance, the thickness of the joiner 55 must be reduced. Mounting two different thickness plates 50 to one joiner 55 also requires a special joiner 55 because an outside-facing shoulder is created where the different thickness plates 50 meet. The shoulder cannot face the interior of the trailer 10 as it becomes a xe2x80x9csnagxe2x80x9d point, causing damage to cargo and causing the plates 50 to be more easily damaged. The special joiner 55 must be designed to accommodate that shoulder. Thus, for conventional plate coupling systems, when the plate 50 increases in thickness the joiner 55 must decrease in thickness to maintain the necessary sidewall thickness 82.
During service, the trailer sidewalls 25 can be damaged, requiring replacement of plates 50, joiners 55, or both. FIG. 4 illustrates a section of sidewall 25 constructed of three plates 50 fixed to two joiners 55 using four rows of fasteners 65. In FIG. 4A, replacement of a plate 50 is illustrated. The plate 50 must be removed from the outside of the trailer 10, because the plate 50 extends past the ceiling and floor 15 of the trailer 10 interior. Thus, both joiners 55 must be removed to remove one plate 50. This requires the removal of four rows of fasteners 65. The time and effort necessary to remove four rows of fasteners 65, and two joiners 55 is significant, which reduces trailer availability, negatively affecting cargo delivery schedules.
FIGS. 5 and 5A illustrate a section of sidewall 25 constructed of three plates 50 fixed to two joiners 55 by four rows of fasteners 65, with logistics members 60. In this arrangement, the four rows of fasteners 65, both joiners 55 and both logistics members 60 must be removed to replace the plate 50. Again, this requires substantial time and effort, resulting in trailer downtime.
Therefore, there exists a need for a trailer plate construction system that permits quick replacement of damaged plates and enables the use of thick plates without exceeding Federal regulations while meeting industry cargo carrying standards.
In order to overcome the deficiencies with known, conventional plate construction systems, a method and apparatus for coupling trailer plates is provided. Briefly, the plate-coupling system of the present invention includes a stepped section located on at least one side of a substantially rectangular trailer plate and an elongated coupler having a plate receiving area. The plate receiving area is configured to receive the trailer plate stepped section.
More specifically, one embodiment of the plate-coupling system employs a substantially rectilinear coupling member comprising an inward-facing and an outward-facing surface. At least two trailer plate receiving areas are located on the outward-facing surface of the rectilinear coupling member. The trailer plate receiving areas are arranged to receive an inward-facing surface of a stepped section of a trailer plate. As defined herein, the outside-facing surface is the surfaces that faces the exterior of the trailer and the inside-facing surface is the surface that faces the interior of the trailer.
Advantageously, the trailer plate coupling system according to the present invention allows the use of increased thickness plates without exceeding Federal trailer width standards. With the present invention, increases in plate thickness do not push the coupling member outward, but rather, the plate is pushed outward. However, the outward-facing surface of the plate does not exceed the outward-facing surface of the coupling member, thereby maintaining a sidewall thickness that meets the Federal regulations and industry standards.
The coupling system according to the invention also permits quick replacement of damaged plates by requiring the removal of the damaged trailer plate only. The coupling member remains attached to the trailer sidewall.
In addition, the coupling system according to the invention also permits plates of different thickness to be coupled adjacent to each other, without the need for special coupling members. Moreover, the coupling system according to the invention can also be used in the construction of intermodal containers, and shipping containers.